Deregulated Hepatic Metabolism Exacerbates Impaired Testosterone Production in Mrp4-deficient Mice
| Autor: | Yao Wang, Wenchen Zhao, Kelli L. Boyd, Satish Cheepala, Mark Leggas, Raman Venkataramanan, Masashi Adachi, Jessica A. Morgan, Geoff Neale, Deepa Nachagari, John D. Schuetz |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Male
endocrine system medicine.medical_specialty medicine.drug_class Biology CREB Biochemistry Gene Expression Regulation Enzymologic Mice Internal medicine Cyclic AMP medicine Animals Humans Testosterone Cyclic AMP Response Element-Binding Protein Cytochrome P450 Family 2 Spermatogenesis Receptor Molecular Biology Mice Knockout Leydig cell urogenital system Leydig Cells Cell Biology Receptors LH Androgen Up-Regulation medicine.anatomical_structure Endocrinology Liver Steroid Hydroxylases biology.protein Aryl Hydrocarbon Hydroxylases Multidrug Resistance-Associated Proteins Luteinizing hormone hormones hormone substitutes and hormone antagonists Homeostasis |
| Zdroj: | Journal of Biological Chemistry. 287:14456-14466 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m111.319681 |
| Popis: | The physiological role of multidrug resistance protein 4 (Mrp4, Abcc4) in the testes is unknown. We found that Mrp4 is expressed primarily in mouse and human Leydig cells; however, there is no current evidence that Mrp4 regulates testosterone production. We investigated its role in Leydig cells, where testosterone production is regulated by cAMP, an intracellular messenger formed when the luteinizing hormone (LH) receptor is activated. Because Mrp4 regulates cAMP, we compared testosterone levels in Mrp4(-/-) and Mrp4(+/+) mice. Young Mrp4(-/-) mice had significantly impaired gametogenesis, reduced testicular testosterone, and disruption of Leydig cell cAMP homeostasis. Both young and adult mice had impaired testosterone production. In Mrp4(-/-) primary Leydig cells treated with LH, intracellular cAMP production was impaired and cAMP-response element-binding protein (CREB) phosphorylation was strongly attenuated. Notably, expression of CREB target genes that regulate testosterone biosynthesis was reduced in Mrp4(-/-) Leydig cells in vivo. Therefore, Mrp4 is required for normal Leydig cell testosterone production. However, adult Mrp4(-/-) mice are fertile, with a normal circulating testosterone concentration. The difference is that in 3-week-old Mrp4(-/-) mice, disruption of gonadal testosterone production up-regulates hepatic Cyp2b10, a known testosterone-metabolizing enzyme. Therefore, defective testicular testosterone production de-regulates hepatic Cyp-mediated testosterone metabolism to disrupt gametogenesis. These findings have important implications for understanding the side effects of therapeutics that disrupt Mrp4 function and are reported to alter androgen production. |
| Databáze: | OpenAIRE |
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